can someone please tell me what the numbers mean after the prounouciation words? I'm guessing they are how the word is pronounced but I can find no reference to which number means which form of pronounciation.

I'm really sorry that this isn't introduced more clearly at the moment - we are working on that right now. In the meantime, you can find a bit of an introduction both in the Mandarin FAQ - www.memrise.com/faq/mandarin - and in the "tone game" - www.memrise.com/tonegame.